Air line lubricator



AIR LINE LUBRICATOR Robert D. Wiley, Detroit, Mich., assignor to Master Pneumatic, Inc., Detroit, Mich, a corporation of Michigan Application April 12, 1957, Serial No. 652,486

3 Claims. (Cl. 184--55) This invention can be used wherever it is desired to deliver a liquid in the form of relatively small particles to a stream of gas passing through a conduit. A typical application of the invention is in delivering lubricating the efiective height of the wick increases so that the rate of delivery of oil to the air stream varies undesirably. Other air line lubricators have heretofore used pressure for forcing the oil from a reservoir into the air stream.v

One objection to such structures is that the oil must usually be forced through a small orifice or a wick like element presenting a relatively small filtering surface and; in either case the structure is subject to being clogged by foreign matter.

An object. of the present invention is to provide a simple inexpensive improved air line lubricator. which will remain free of clogging and in which the rate of delivery of oil to the air stream will remain uniform.

The invention is carried out generally by mounting a wick within a container separate from the oil reservoir. and providing an aspirator for delivering oil from the reservoir to the containerv at a rate faster than it is removed by the wick. The container is provided with an overflow opening so that the level of oil in the container remains uniform and the rate of capillary flow of oil from the container to the portion of the wick within the airstream remains uniform. The-wick is dimensioned to; provide a large filtering surface so that it may be used, indefinitely without clogging. One form of the invention is shown in the accompanying drawings:

Fig. 1 is a generally sectional view of an air line lub- Fig. 2 is a top plan view of the lubricator with parts 55 ricator according to this invention.

shown in phantom to illustrate structure. 6

Fig. 3 is a fragmentary sectional view on line 3-3 of Fig. 2. I v Fig. 4 is a sectional view on line 44 of Fig. 1. j Fig. 5 is an enlarged fragmentary sectional view illustrating structure at the aspiration port.

Shown in Fig. 1 is a lubricator having a body formed by a cup 11 defining a chamber 12 which is closed by a cap 13 detachably secured to the cup by, such means as a threaded retainer ring 14. Chamber 12 provides a reservoir for lubricating oil 15. Cup 11 is preferably provided at its bottom with a drain opening 16 having a drain cock 17 threaded-therein. Cap 13 has a passageway 20 with an inlet 21 and an outlet 22- threaded for connection to. portions of a conduit 23for carrying air under pressure. Passageway 20 has an inter- 13 for suspending the container in chamber 12. A

wick member 33 is mounted within container 30 and has and upper portion 34 which projects through an opening 35' in cap 13 into the constricted portion 24 of passageway 20. The wick is preferably formed of a generally rigid material such as a sintered metal and is supported at its lower end 36 by a screw 37 having a threaded connection to an element 38 press fitted into the bottom portion of container 30 as shown. An 0 ring 39 provides a seal between the shank of screw 37 and adjacent portions of the container bottom. Wick 33 fits nicely but slidably in cap opening 35 so that the height of the wick portion exposed within passageway 20 can be adjusted by turning screw 37. A spring 40 seats on the upper end of the wick and reacts against cap 13 for urging the wick against supporting screw 37. Wick 33 extends a considerable distance into container 30 and the side walls 41 of the container are spaced from the sides of the wick by an appreciable distance as shown.

An aspirator structure is provided for transferring oil from the main reservoir formed by chamber 12 into container 30 for contact with wick 33. This aspirator generally speaking comprises a shunt passageway extending from a portion of passageway 20 upstream of constriction 24, through an interior portion of container 30, and then to constriction 24; an aspiration port is provided in the shunt below the normal level range of oil in the main reservoir. In the illustrated form of the invention cap 13 is provided with a port 44 opening into main passageway 20 upstream of constriction 24 and registering with an end of a passageway 45 formed in a wall of container 30. A fitting 46 connects the downstream end of passageway 45 with another passageway 47 formed in the container wall. Fitting 46 and the upstreamend of passageway 47 cooperate to define a relatively small aspiration port 48 disposed below the normal level. of oil in the main reservoir. The cooperating portions of fitting 46 and passageway 47 are shown as being tapered so-that the aspiration port has generally annular conical form. The downstream end of passagewayv47 opens.'into the upper portion of container 30 as at 49..

Container 30 has a port 52 adjacent its upper end which opens into chamber 12. Cap 13 has a vent passageway 54- extending from the upper portion of chamber 12 to constricted portion 24 of main passageway 20. This completes the shunt system which provides the aspirator for transferring oil from the main reservoir to container 30.

' Shunt passageway 54 opens into chamber 12 at an angle I to the depth dimension of chamber 12 for a purpose to be described. An air scoop 53 may be provided as shown at port 44 to assist entry of air into the aspirator system. In use, it may be assumed that the inlet 21 and outlet 22 of main passageway 20 have been connected into air conduit 23 and that lubricating oil has been placed in the reservoir formed by chamber 12. It may also be assumed that wick 33 has been primed or dampened with oil and that container 30 has been filled. The height of wick 33- has been adjusted to expose a desired portion of the wick to the interior of passageway 20. When air under pressure is passed through conduit 23 in the direction indicated by the arrows (Fig. 1) it passes through constricted portion 24 at a relatively high velocity and relatively low pressure according to well known principles and picks up Patented Mar. 24,, 1959 oil in small particles in the form of a spray or mist and delivers the oil to the equipment to be operated and lubricated.

The pressure at port 44 is, greater than the pressure at the downstream end" at 56 off'vent'54 which is disposed at constriction 24. Accordingly, an air stream flows through port 44', passageway 45, fitting 46 and past aspiration port 48into passage 47. From there the stream flows through outlet 49 into the upper interior portion of container 30, out of the container through port 52, and into the upper portion of chamber 12'. From there the stream passes outof chamber 12 through vent 54 and returns to passageway at constriction 24.

Asthe stream passes aspiration port 48 it picks up oil in pa ticulate or spray or mist form and carries it to the atsiuor: o ontai er e on ner interior has a reat r sectiona re an. hat o passa e y 47 sothat he-veloci y f the libe r n a r; diminish s as it: en s hecpa a uer and q .l. s QQPQ EQQ n. he o ta e T s depo ting; Qf he oi isass s di yi r ie h r t eam r d w c 3 The. h nt p s y ys and aspiration port 48 are arranged. so that oil is thus transferred'from the main reservoir into container 30 at a rate at least as great as it is removed from container 39: by wick 33. Port 52 provides an overflow for any excess oil: which may be delivered to container 30, theoverflowing oil returning to the main reservoir as will beapparent from Fig, l. The, level of oil in container 30 is maintained uniform at the level of the overflow as illustrated. Accordingly, there is a uniform capillary flow through wick 33' to its portion 34 exposed to the air stream in main passageway 20, The rate of" this capillary flow remains uninfiuenced' by the level of oil' in cup 11. As a result, oil is fed to the main air stream at a uniform rate regardless of the oil'level in cup. 11.

The portion of wick 33 contacted by oil in container 30.jis relatively long and the surface of contact is relatively great so that the pores of the wick will not be readily clogged by foreign matter in the oil because of the filtering effect of the wick. Accordingly, the lubricator may be used'over a long period of time without stoppage due, to clogging.

The, velocity of the air diminishes further as it enters chamber 12 through port 52 so that any excess of oil which it still carries will for the mostpart be deposited in the chamber. The angled direction of vent 54 results in a relatively smooth flow of air from port 52 through chamber 12 and minimizes turbulence within the cham her and increases; the eflijciency of the aspirator system.

When the flow of air through passageway 20 ceases, the oil" level in container 30 will remain substantially at overflowport 52 and the exposed end portion 34 of the wick will remain fully-dampened andready for immediate sumption of its lubricating function when air again passes through the passageway. Thus, cup 11 may be drained; such as for cleaning purposes, by opening cock 17,1 or cup 11 may even be removed from cap 13 for cleaning or maintenance purposes without substantially affecting, the condition ofthe wick.

When'the air flow in passageway 20 is interrupted, liquid may rise in passageways 45 and 47 through port 48-toward the levelof oil'in cup 11. However when the air flow is resumed, the oil in these passageways is discharged and there is no appreciable delay in functioning ofthe aspirator system.

Thervolume of lubricant delivered to the air stream in-conduit 23 may be varied as desired by adjusting the heightrof exposed portion 34 of the wick in constriction 24;, Thisis done by turning screw 37 to raise or lower thewick, Spring 'insures downward'movement of the wick with screw 37 when the screw is retracted.

The presentrinvention makes it possible to provide adequate lubrication'fluid to a high,volume of air over a relativelylong period of time-,at a uniform rate and without malfunctioning,

I claim:

1. In an air line lubricator having a passageway adapted to be connected to a conduit for air under pressure, a cup for containing lubricant and an elongate wick extending into said cup and into said passageway, means providing a bath of lubricant of uniform depth around said wick comprising, an envelope surrounding substantially the entire length of the portion of said wick extending into said cup, said envelope having a closed bottom below the lower end of said wick and forming a, container which is separate from said cup, said container having an open portion adjacent the uppermost, region of the portion of the wick extending into said cup, flow diverting means operative to divert a flow of air from said passageway, meansoperable-by saidv flow of air to transfer lubricant in said cup to said open portion of said container at a rate exceeding the rate at which said wick delivers lubricant to said passageway, whereby to maintain a bath of lubricant around said wick having a generallyuniform depth equal to the depth of said container from its bottom; to said open portion, the portion of said wick adjacent said open portion being exposed to the pressure of air within said cup above the lubricant level, said flow diverting means including a vent for exhausting said flow of air to said passageway at a location predetermined to provide a relativelysmall diiierential between the air pressureon thelatter said portion of said wick and the air pressure onthe portion thereof extending into said passageway, so that said wick feeds lubricant to said passageway by capillarity at a rate substantially unaffected by thepressure of the air in said cup.

2. In an air line lubricator having apassageway adapted to be connected to a conduit for air under pressure, a cup for containing lubricant and an elongate wick extending into said cup and intosaid passageway, means providing a bath of lubricant of uniform depth around said wickcomprising, an envelope surrounding substantially the entire length of theportion of said wick extending into said cup, said envelope having aclosed bottom below'the lower-end of said wickand forming a container whichis separate from said cup, said container having an open portion adjacent the uppermost region of the portion of the wick extending into said cup, fiow diverting means operative to divert afl'owof air from said passageway, means operable by' said flow of airto transfer lubricant insaid cup to saidopen portion of said container at a rate exceeding the rate at which said wick delivers lubricant to said passageway, whereby to maintain a bath of lubricantaround'said wick having a generally uniform depth-equal" to'the'depth of said container from its bottom to said 'open portion, the portion of said wick adjacent said open portion being exposed to the pressure of air withinsaid cup above-the lubricant level, said flow diverting means including a vent for-exhausting said'flow of air to-said 'passageway; said" vent being open to said cup and opening into said passageway at a location closely adjacent the portion of said wick which extends into said passageway to providea relatively small difierential between the air pressure on the latter said portion of said wick-and the air 'pressureon the portion thereof adjacent said open portion of saidcontainer, so that said wick feeds-lubricant to said passageway by capillarity at a rate substantially unafiected by the pressure of the airin said cup. 1

3. In an air line lubricator having a passageway adapted to be connected to a conduit for airunder pressure, said passageway having aconstricted portion, a cup for containing lubricant, andan elongate wick extendingintosaid cup and into said constricted portion of said passageway, means providing a bath of lubricant of uniform. depth around-said wick comprising, an envelope surroundingsubstantially the entire length of the portion ofsaidwick extending'into said cup, said envelope hav ing ag closed bottom below the lower end of said wick and forming a container which is separate from saidcup, said container having an open portion adjacent the uppermost region of the portion of the wick extending into said cup, flow diverting means operative to divert a flow of air from said passageway, means operable by said flow of air to transfer lubricant in said cup to said open portion of said container at a rate exceeding the rate at which said wick delivers lubricant to said passageway, whereby to maintain a bath of lubricant around said wick having a generally uniform depth equal to the depth of said container from its bottom to said open portion, the portion of said wick adjacent said open portion being exposed to the pressure of air within said cup above the lubricant level, said flow diverting means including a vent which is open to said cup and which opens into said passageway at References Cited in the file of this patent UNITED STATES PATENTS 1,504,341 Hansen Aug. 12, 1924 2,718,934 Norgren et al Sept. 27, 1955 2,767,807 Booth Oct. 23, 1956 

